i have some mods n the morph crashes the game when used in creative, survival works just fine
https://pastebin.com/aZ0u3MdA

Possibly duplicate of #277

72a087a will fix this from crashing your game completely. The problem is that some mobs assume they aren't being rendered in a GUI (or something like that); going into creative mode, which shows all entities, is the perfect way to trigger the issue.